The intention behind her crosswalk makeover was to ensure the safety of pedestrians while bringing people together.

The effect of Whitty’s highly visible installation was immediate. Motorists normally whip past that intersection, but this time they slowed. Pedestrians stopped to talk before crossing safely at a juncture known for jaywalking. The intersection had been dangerous and impersonal. Whitty’s efforts made it safe and welcoming. A simple intervention changed people’s interactions with a dense urban street.

This is tactical urbanism — city residents building DIY projects that foster community.

Canada’s population is growing faster than ever and cities account for nearly 80 per cent of that growth. Expanding cities are struggling to stay green, and to keep a sense of community with larger populations. As more people (and more families) become condo dwellers, well-designed public spaces make anonymous urban cores more livable, creating smaller pockets for lingering conversations, public gatherings or safe play for kids.

While city planners focus on roads, essential services and power connections, most tactical urbanism projects are about building social spaces.

“For a long time, city planning was centralized. You had planners, politicians and architects imagining the city into being,” says landscape architect Jill Robertson, a colleague of Whitty at Edmonton’s Dialog design firm. “With tactical urbanism, it’s a participatory process.”

Pedestrian-friendly intersections are just one example. In 2014, red swings were installed overnight in trees around Halifax, turning little-used green spaces into pop-up playgrounds. Every summer since 2013, donated pianos placed around Vancouver have inspired impromptu concerts. What these do-it-yourself initiatives share is a goal of deepening our interactions with our cities and neighbours.

These projects may sound quirky, but they offer a powerful solution to one of the most entrenched problems we face today — deepening divisions between people and among neighbourhoods.

Public space is an inoculation against this division. Halifax’s swings are open to anyone. Vancouver’s concerts attract people who may not otherwise meet. And DIY projects give people a reason to get to know their neighbours.

We can make our world better by investing in our communities and creating common experiences for all. “Everyone can play a role in this,” says Whitty, pointing to two annual theme days that are gaining traction and serve to get anyone — not just architects or designers — involved.

The first is Park(ing) Day, started in San Francisco in 2005 and has gone global. Every year, on the third Friday in September, community members turn unused spaces in their neighbourhoods (mostly parking spots) into parks, complete with ping-pong tables, Muskoka chairs and potted trees.

On 100In1Day, urbanites dream even bigger, transforming their cities through hundreds of co-ordinated interventions in public spaces over one day in June.

Little parklets or small community projects may not seem like they’re saving the world, but our cities and neighbourhoods are what bind us together. We could all stand to invest more in our sense of belonging.

Craig and Marc Kielburger are the co-founders of the WE movement, which includes WE Charity, ME to WE Social Enterprise and WE Day. For more dispatches from WE, check out WE Stories.